unrpa.py

#!/usr/bin/env python2

'''
  This program is free software: you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation, either version 3 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.

        You should have received a copy of the GNU General Public License
        along with this program.  If not, see <http://www.gnu.org/licenses/>.
'''

### Copyright Gareth Latty 2009

### Version 1.4 (Current)
### make_directory_structure improved.

### Version 1.3
### BUGFIX: Presumed that the RPA archive would use the path seperator of the
###         system. Broke under some circumstances.

### Version 1.2
### BUGFIX: Presumed a forwards slash in the make_directory_structure function,
###         Broke under windows when using --mkdir.

### Version 1.1
### BUGFIX: Crash upon listing files when in verbose mode.
### BUGFIX: A few extra bytes were appended to the end of every file.

### Version 1.0
### Initial Release

import os
import optparse
import sys
import pickle

class UnRPA:

        verbose = None
        path = None
        mkdir = None
        version = None
        archive = None

        def __init__(self, filename, verbosity=1, path=None, mkdir=False, version=None):
                self.verbose = verbosity
                if path:
                        self.path = os.path.abspath(path)
                else:
                        self.path = os.getcwd()
                self.mkdir = mkdir
                self.version = version
                self.archive = filename

        def extract_files(self):
                if self.verbose > 0:
                        print("unrpa: extracting files.")
                if self.mkdir:
                        self.make_directory_structure(self.path)
                if not os.path.isdir(self.path):
                        sys.exit("unrpa: error: path doesn't exist, if you want to create it, use -m.")
                index = self.get_index()
                for item, data in index.iteritems():
                        self.make_directory_structure(os.path.join(self.path, os.path.split(item)[0]))
                        raw_file = self.extract_file(item, data)
                        with open(os.path.join(self.path, item), "wb") as f:
                                f.write(raw_file)

        def list_files(self):
                if self.verbose > 1:
                        print("unrpa: listing files:")
                index = self.get_index()
                paths = index.keys()
                paths.sort()
                for path in paths:
                        print(path)

        def extract_file(self, name, data):
                if self.verbose > 1:
                        print("unrpa: extracting file: " + name)
                if len(data[0]) == 2:
                        offset, dlen = data[0]
                        start = ''
                else:
                        offset, dlen, start = data[0]
                with open(self.archive, "rb") as f:
                        f.seek(offset)
                        raw_file = start + f.read(dlen - len(start))
                return raw_file

        def make_directory_structure(self, name):
                if self.verbose > 2:
                        print("unrpa: creating directory structure:" + name)

                if not os.path.exists(name) and not os.path.isdir(name):
                        os.makedirs(name)

        def get_index(self):
                if not self.version:
                        if os.path.splitext(self.archive)[1].lower() == ".rpa":
                                with open(self.archive, "rb") as f:
                                        self.version = self.determine_version(f.readline())
                        elif os.path.splitext(self.archive)[1].lower() == ".rpi":
                                self.version = 1
                if self.version == 3:
                        with open(self.archive, "rb") as f:
                                l = f.readline()
                                offset = int(l[8:24], 16)
                                key = int(l[25:33], 16)
                                f.seek(offset)
                                index = pickle.loads(f.read().decode("zlib"))
                                index = self.deobfuscate_index(index, key)
                elif self.version == 2:
                        with open(self.archive, "rb") as f:
                                offset = int(f.readline()[8:], 16)
                                f.seek(offset)
                                index = pickle.loads(f.read().decode("zlib"))
                elif self.version == 1:
                        with open(self.archive, "rb") as f:
                                index = pickle.loads(f.read().decode("zlib"))
                else:
                        sys.exit("unrpa: error: file doesn't look like an archive, if you are sure it is, use -f.")
                if not "/" == os.sep:
                        final = {}
                        for item, data in index.iteritems():
                                final[item.replace("/", os.sep)] = data
                        return final
                else:
                        return index

        def determine_version(self, line):
                if line.startswith("RPA-3.0 "):
                        return 3
                if line.startswith("RPA-2.0 "):
                        return 2
                else:
                        return None

        def deobfuscate_index(self, index, key):
                for k in index.keys():
                        if len(index[k][0]) == 2:
                                index[k] = [ (offset ^ key, dlen ^ key) for offset, dlen in index[k] ]
                        else:
                                index[k] = [ (offset ^ key, dlen ^ key, start) for offset, dlen, start in index[k] ]
                return index

if __name__ == "__main__":
        parser = optparse.OptionParser(usage = "usage: %prog [options] pathname", version="%prog 1.1")

        parser.add_option("-v", "--verbose", action="count", dest="verbose", help="explain what is being done [default]")
        parser.add_option("-s", "--silent", action="store_const", const=0, dest="verbose", default=1, help="make no output")
        parser.add_option("-l", "--list", action="store_true", dest="list", default=False, help="only list contents, do not extract")
        parser.add_option("-p", "--path", action="store", type="string", dest="path", default=None, help="will extract to the given path")
        parser.add_option("-m", "--mkdir", action="store_true", dest="mkdir", default=False, help="will make any non-existant directories in extraction path")
        parser.add_option("-f", "--force", action="store", type="int", dest="version", default=None, help="forces an archive version. May result in failure.")

        (options, args) = parser.parse_args()

        if not len(args) == 1:
                if options.verbose:
                        parser.print_help()
                parser.error("incorrect number of arguments.")

        if options.list and options.path:
                parser.error("option -p: only valid when extracting.")

        if options.mkdir and not options.path:
                parser.error("option -m: only valid when --path (-p) is set.")

        if options.list and options.verbose == 0:
                parser.error("option -l: can't be silent while listing data.")

        filename = args[0]

        unarchiver = UnRPA(filename, options.verbose, options.path, options.mkdir, options.version)
        if options.list:
                unarchiver.list_files()
        else:
                unarchiver.extract_files()